The present invention relates to a drive system, more precisely relates to a drive system having a rack-pinion mechanism.
Drive systems having a rack-pinion mechanism have been known. For example, European Patent Gazette EP-265-855-A disclosed a drive system having a rack-pinion mechanism. The system has a pair of pinions which are coaxially connected by a shaft. The shaft is rotatably pierced through a moving body. The pinions are respectively engaged with a pair of racks, which are provided in a first direction in parallel, and the pinions are rotated by a motor attached to the one end of the shaft. When the motor is driven, the shaft is rotated together with the pinions. Rotating pinions roll over the racks, so that the moving body moves in the first direction. In the above described drive system, since the pinions are engaged with the parallel racks and connected to the shaft, the positioning accuracy of the moving body can be quite high.
However, in the drive system, the motor moves together with the moving body, the shaft, etc., so that the weight of the motor, which is relatively quite heavy, becomes a load oh the motor. The heavy load causes disadvantages such as greater energy consumption and an obstacle to high speed operation.